In a wireless communication network, generally, a call processing log is stored in a network-side communication apparatus, and quality monitoring is performed based on a communication quality index value calculated from the log.
As an example, the wireless base station control apparatus of a mobile communication network based on the specifications of 3GPP (3rd Generation Partnership Program) measures and records the attempt and failure counts of radio access bearer establishment, handover, and the like for each wireless cell as a call processing log to be transmitted/received to/from a mobile terminal on the control plane, as defined in reference “3GPP TS 32.403, “Telecommunication management; Performance management (PM); Performance measurements—UMTS and combined UMTS/GSM (Release 7)”, 2005” (to be referred to as reference 1 hereinafter). The wireless base station control apparatus obtains KPI (Key Performance Indicator) values such as a radio access bearer establishment failure rate and a handover failure rate, which are defined in reference “3GPP TS 32.410, “Telecommunication management; Key Performance Indicators (KPI) for UMTS and GSM (Release 8)”, 2008” (to be referred to as reference 2 hereinafter), from the measured values and uses them for quality monitoring.
Another technique is also known, which causes not the network-side communication apparatus but a mobile terminal to measure quality information and causes a server to collect the quality information by transmission on the user plane and monitor communication quality.
For example, a system disclosed in Japanese Patent Laid-Open No. 2008-109571 statistically processes network quality information collected from mobile terminals for each unit area, calculates quality statistics in each unit area, and uses them for quality monitoring.
There is also known a technique of causing a mobile terminal to control communication quality. For example, a mobile communication system disclosed in Japanese Patent Laid-Open No. 2008-092421 causes a mobile terminal to detect the moving speed of its own and determine a communication data format for wireless communication with a wireless base station based on the detected moving speed.